Before you start writing your script, you need to decide what format your documentary will follow. There are different types of documentary formats, such as observational, expository, participatory, poetic, reflexive, and performative. Each one has its own advantages, disadvantages, and conventions. For example, observational documentaries rely on capturing reality as it unfolds, without narration, interviews, or commentary. Expository documentaries use voice-over, graphics, and archival footage to present a factual argument or perspective. Participatory documentaries involve the filmmaker as a character or a participant in the story, creating a personal or subjective point of view. Poetic documentaries use visual and sound techniques to create a lyrical or expressive impression of a theme or a mood. Reflexive documentaries draw attention to the process and the ethics of documentary filmmaking, challenging the notions of objectivity and representation. Performative documentaries use dramatization, re-enactment, or performance to explore a personal or social issue. You should choose the format that best suits your topic, your style, and your purpose.